Device-to-Device (D2D) wireless communication techniques may be used to perform peer-to-peer/point-to-point (P2P) communications among mobile devices and networks in a variety of settings. D2D communications between mobile devices may be designed to complement the use of centralized communications from a wireless base station, for example, centralized station-to-mobile communications from an evolved NodeB (eNodeB) in a carrier network operating with a standard from a 3GPP Long Term Evolution/Long Term Evolution-Advanced (LTE/LTE-A) standards family, or from an access point (AP) in a Wi-Fi network operating with a standard from a Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards family.
D2D direct communications are limited to devices located within the communication range of the wireless protocol or network configuration being used. However, a particular user may not be aware whether D2D communication-capable devices or known users associated with D2D communication-capable devices are within communication range, or whether such devices or users are currently or are prospectively in proximity to the particular user.
In current Device-to-Device (D2D) technologies, UEs advertise and/or search for advertisements from other UEs in order determine whether they are in D2D range. However, this results in a waste of radio and battery resources. To address this issue, a UE may request help from the network to determine if/when another UE is in proximity and, when proximity is detected, expedite the process of direct discovery. This process is referred to as network-assisted device discovery. In network-assisted device discovery, the network may monitor UE locations and inform UEs when there is a high probability that they are in range. Then do UEs engage in direct discovery to confirm that they are in D2D range.
Network assisted device discovery significantly reduces resource waste. However, there are some cases when a UE has requested proximity detection of a large number of UEs over the same period of time. In such cases, it may be more resource efficient to switch the UE to Direct Discovery once the network determines that large numbers of the requested UEs are approaching the UE's proximity.